Device capable of reading plural documents, method of controlling the device, and program

ABSTRACT

Provided is a device that prevents unauthorized copying of a document to which copy inhibition information is added.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.13/592,048, filed Aug. 22, 2012, which is a Continuation of U.S. patentapplication Ser. No. 12/753,680, filed Apr. 2, 2010, now U.S. Pat. No.8,274,709, which is a Continuation of International Application No.PCT/JP2009/069174, filed Nov. 11, 2009, which claims the benefit ofJapanese Patent Application No. 2009-184800, filed Aug. 7, 2009, all ofwhich are hereby incorporated by reference herein in their entirety.

TECHNICAL FIELD

The present invention relates to a device capable of reading pluraldocuments, a method of controlling the device, and a program.

BACKGROUND ART

In recent years, unauthorized copying of documents has become morefrequent as a result of the spread of copiers. A technique is providedas a countermeasure that inhibits copying of a specific document. Thetechnique that inhibits copying is as follows.

A copier disclosed in patent literature 1 adds copy inhibitioninformation to a document. When the copier reads the document, thecopier inhibits copying of the document.

A copier disclosed in patent literature 2 adds conditional copypermission information and a condition (for example, a password) to adocument. When the copier reads the document, the copier requests a userto input the condition added to the document. If the input condition iscorrect, the copier makes a copy of the document. If the input conditionis wrong, the copier does not make a copy of the document.

CITATION LIST Patent Literature

-   PTL 1: Japanese Patent Laid-Open No. 04-009963-   PTL 2: Japanese Patent Laid-Open No. 2002-305646

SUMMARY OF INVENTION Technical Problem

However, if a malicious user wants to make an unauthorized copy of adocument to which copy inhibition information is added, such a user maythink as follows.

I have a document to which conditional copy permission information and acondition are added. Fortunately, I know the condition (for example, apassword). When I put the document on a document plate, the copier wouldask me to input the condition. At this time, I can input the conditioncorrectly. As long as I can input the condition correctly, the copierhas no other choice but to make a copy of the document on the documentplate. So I try to put the document to which the conditional copypermission information is added, together with a document to which copyinhibition information is added. Then, a copy of the document to whichthe copy inhibition information is added should be made. Such amalicious user may think as described above, and make an unauthorizedcopy of the document.

The present invention is made to inhibit the malicious user from makingan unauthorized copy of the document. Also, other output techniques (forexample, techniques of sending e-mails, facsimiles, etc.) may have aproblem similar to the above-described problem.

Solution to Problem

A device according to an embodiment of the present invention includesgenerating means for reading a plurality of documents and generatingdocument images corresponding to the documents; and extracting meanscapable of extracting conditional output permission information andoutput inhibition information from the generated document images. If theconditional output permission information and the output inhibitioninformation are extracted by the extracting means, the generateddocument images are not output. Accordingly, unauthorized outputting bya malicious user can be inhibited.

Also, a device according to an embodiment of the present inventionincludes reading means for reading a document that is inhibited frombeing output and a document that is conditionally permitted to beoutput; and inhibiting means for inhibiting the documents read by thereading means from being copied.

Advantageous Effects of Invention

With the present invention, the behavior of a malicious user can beprevented when the user intends to make an unauthorized copy of adocument that is inhibited from being output.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram of a MFP according to a first embodiment.

FIG. 2 is a flowchart showing a document creation process of the MFP.

FIG. 3 illustrates a part of a bar code plotted with a reference grid.

FIG. 4 illustrates a method of finding a bar code from a document image.

FIG. 5 illustrates a bar code.

FIG. 6 illustrates examples of screens for setting specific information.

FIG. 7 is a flowchart showing a flow of copy control executed by theMFP.

DESCRIPTION OF EMBODIMENTS

Preferred embodiments of the present invention will be described belowwith reference to the attached drawings.

First Embodiment

A copy of a document to which conditional copy permission informationand a condition are added can be made only if the condition issatisfied. Owing to this, for example, if a user who knows the conditionof the document inputs the condition correctly to a copier and intendsto make a copy of the document, the copier has no choice but to make acopy of the document.

A first embodiment of the present invention aims at such a user who usesthe document to make a copy of another document to which copy inhibitioninformation is added. In particular, in this embodiment, the user is notonly inhibited from making a copy of another document, but also frommaking a copy of the document (the document to which the conditionalcopy permission information and the condition are added) as a penalty.

Now, words used in the first embodiment of the present invention will bedescribed. Specific information represents any information listed below.First specific information includes two pieces of information of copyinhibition information and a document ID. Second specific informationincludes three pieces of information of conditional copy permissioninformation, a condition, and a document ID. Also, in the firstembodiment of the present invention, the copy inhibition information andthe conditional copy permission information are collectively called copycontrol information.

Next, a process of creating a document to which specific information isadded will be described. Firstly, specific information is encoded toacquire embedded information. Secondly, an image of the embeddedinformation is formed to generate a bar code. The generated bar code isreplicated. The resulting plurality of bar codes are combined togenerate a bar code group. Thirdly, the bar code group is merged with adocument image, to generate a document image with the bar codes merged.Lastly, the document image with the bar codes merged is printed.Accordingly, a document to which the specific information is added inthe form of the bar codes is created. The process series is called“addition” of the specific information. Also, the process of encodingthe specific information to form an image of the specific information(with this process, a bar code is generated) is called bar-coding of thespecific information.

The bar code group, in which the plurality of bar codes are combined, ismerged with the document image and printed, in order to obtain an effectof increasing resistance characteristics. Since the bar code group ismerged with the document image and printed, the specific information canbe extracted from the document as long as at least a single bar code ispresent in the document in an uncontaminated manner.

In the following embodiments including the first embodiment of thepresent invention, processes in respective steps in a mode, in which abar code group is used (a mode in which the bar code group is mergedwith the document image and printed, and a mode in which the printeddocument is read and copying of the document is controlled), will bedescribed for example. However, a mode in which only a single bar codeis merged with a document image and printed, and a mode in which theprinted document is read and copying of the document is controlled, maybe conceived although the above-described effect is degraded.

In this embodiment, the number of bar codes included in a bar code groupcorresponds to the size of a document image. For example, when thedocument image has a size that is printed on an A4-size (21×29.7 cm)sheet, a bar code group includes 21×29 bar codes. Accordingly, bar codesare included in the entire area of the created document.

Next, a process of extracting specific information from a document, towhich the specific information is added in the form of bar codes, willbe described. Firstly, a document put on a document plate or an autodocument feeder (ADF) is read, and a document image of the read documentis generated. Secondly, bar codes are found from the document image.Thirdly, information in the found bar codes is acquired to acquireembedded information. Fourthly, the embedded information is decoded toacquire specific information. Accordingly, the specific information canbe acquired from the document to which the specific information is addedin the form of the bar codes. The second and later processes in theprocess series is called “extraction” of the specific information.

The embedded information includes an error correction code, but thespecific information does not include an error correction code.

A configuration of a multi function peripheral (MFP) according to thefirst embodiment of the present invention will be described in detailwith reference to FIG. 1. FIG. 1 is a block diagram showing theconfiguration of the MFP according to this embodiment.

A control unit 1 controls operations of respective units in the MFP. Thecontrol unit 1 includes a central processing unit (CPU) (not shownhere). The control unit 1 also decodes embedded information.

An operation unit 5 receives an operation input to the MFP from a user.

A user authentication unit 6 manages information required forauthenticating a user who uses the MFP. The operation of the userauthentication unit 6 will be described later in more detail.

A reading unit 2 reads (for example, scans) the document and generates adocument image of the document. It is to be noted that a document is apaper document such as a printed matter, whereas a document image isdigital (or analog) data.

An information acquisition unit 3 finds a bar code from the documentimage, and acquires information in the bar code.

A memory 7 stores the document image.

An output unit 8 outputs the document image after the memory 7 reads thedocument image. For example, the output unit 8 prints the documentimage, or sends the document image to an external device. Herein, theexternal device is, for example, a PC that is connected with the MFPthrough a network.

A display unit 9 displays a display screen under the control of thecontrol unit 1.

A data base 10 performs print setting for the MFP and records a log ofuse.

An encoding unit 11 performs encoding and image formation as describedabove.

Next, an operation performed by a user and a process performed by theMFP in accordance with the operation by the user to add specificinformation will be described in detail.

A user who wants to add specific information to a document inputs a userID and a password through the operation unit 5 while watching a settingscreen 3002 displayed on the display unit 9.

The information input through the operation unit 5 is sent from theoperation unit 5 to the user authentication unit 6. The userauthentication unit 6 determines whether the input password is correctwith reference to the managed information.

If it is determined that the password is correct, the userauthentication unit 6 sends the determination of the correct passwordand the user ID to the control unit 1.

The control unit 1 that has received the determination of the correctpassword and the user ID causes the display unit 9 to display a checkbox (not shown here). The check box has an item by which the user canselect whether specific information is added. If the user checks the boxthrough the operation unit 5, the control unit 1 causes the display unit9 to display a print security setting dialogue box 31 shown in FIG. 6(a).

Next, the user may check one of radio buttons 32 in the print securitysetting dialogue box 31 through the operation unit 5. Then, the user canselect one of an option to “inhibit copy” and an option to “setcondition for permitting copy.” If the selected option is to “inhibitcopy,” copy inhibition information and a document ID are added asspecific information to a document to be printed (which will bedescribed later). If the selected option is to “set condition forpermitting copy,” conditional copy permission information, a documentID, and a condition are added as specific information to a document tobe printed (which will be described later).

If the user selects to “set condition for permitting copy,” a conditioninput field 33 is allowed to be input, and the user may input thecondition (for example, a password or a user ID) in the field. If thecondition is a password, the user may input a password at this time. Ifthe condition is a user ID, the user does not have to input a user ID atthis time, and may input merely selection of the user ID as thecondition. This is because the user ID has been already input for userauthentication.

It is to be noted that the same document ID is added to documentscreated by a single copy operation. Herein, the single copy operation iscopying of a set of documents put on the document plate or the ADF by asingle instruction for copying.

Thus, for example, it is assumed that a user puts a set of documents(for example, 4 sheets) on the ADF and gives an instruction to the MFPfor making three sets of copies. In this case, the three sets of copies(that is, 12 sheets) are created by a single copy operation. The samedocument ID is added to the three sets of copies.

Specific information may be added by an input through a driver or autility in the PC connected with the MFP. In the first embodiment of thepresent invention, the copy control information which is added to asingle document is only one of the copy inhibition information and theconditional copy permission information.

Next, a method of creating a document including a bar code will bedescribed in detail with reference to FIG. 2. FIG. 2 is a flowchartshowing a document creation process of the MFP.

The control unit 1 determines whether the box is checked (S101).

If it is determined that the box is checked in S101, the control unit 1uses the print security setting dialogue box 31 to receive the selectionof the user through the operation unit 5. Then, the control unit 1 sendsspecific information corresponding to the selection to the encoding unit11 (S102). As described above, if the selected option is to “inhibitcopy,” the specific information corresponding to the selection includescopy inhibition information and a document ID. If the selected option isto “set condition for permitting copy,” the specific informationcorresponding to the selection includes conditional copy permissioninformation, a document ID, and a condition.

Next, the reading unit 2 reads a document, generates a document image,and sends the generated document image to the memory 7 and theinformation acquisition unit 3 (S103).

Next, the encoding unit 11 encodes the specific information and forms animage of the specific information to generate a bar code. Also, theencoding unit 11 replicates the bar code by the number corresponding tothe size of the document image (for example, 608 bar codes). Then, theencoding unit 11 combines the resultant plurality of bar codes (forexample, 609 bar codes) to generate a bar code group, and sends the barcode group to the memory 7 (S104).

Next, when the control unit 1 detects that the memory 7 has received thebar code group and the document image, the memory 7 merges the bar codegroup with the document image to generate the document image with thebar codes merged (S105). As described above, in this embodiment, theplurality of bar codes are combined to generate the bar code group, andthe generated bar code group is merged with the document image. Thus,the document image with the bar codes merged is generated.Alternatively, a similar image may be generated even if the process ischanged such that bar codes are repeatedly merged with a document imageone by one.

Next, the control unit 1 sends the document image with the bar codesmerged from the memory 7 to the output unit 8, and causes the outputunit 8 to output the document image (S106). A method of outputting thedocument image by the output unit 8 may be, for example, printing of thedocument image. When the document image is printed, a copy of thedocument that is the original of the document image is made.

If a check box 2011 is not checked, the reading unit 2 reads thedocument, generates the document image, and sends the generated documentimage to the memory 7 (S107). Next, when the control unit 1 detects thatthe memory 7 has received the document image, the control unit 1 causesthe memory 7 to send the document image to the output unit 8, and causesthe output unit 8 to output the document image (S108).

Next, the bar code will be described in detail with reference to FIGS. 3and 5. FIG. 5 illustrates a bar code. FIG. 3 illustrates a part of thebar code plotted with a reference grid.

Reference sign 1600 in FIG. 5 denotes a bar code having a size of about1×1 cm. The bar code 1600 has two types of regions includinghigh-density regions (1605 to 1608) and low-density regions (1609 to1612).

Each high-density region includes encoded copy control information, andeach low-density region includes an encoded condition. Although it isdescribed later, the condition included in the low-density region may bedirectly a condition or may be a hashed condition. If a condition is notpresent, that is, if the high-density region includes copy inhibitioninformation (in a case of a second embodiment, copy inhibitioninformation or copy permission information), the low-density regionincludes dummy information (meaningless information). The high-densityregion uses a large number of error correction codes as compared withthe low-density region.

The high-density region is smaller than the low-density region althoughthe error correction codes are used by a large number because the copycontrol information has a smaller data size than the data size of thecondition. In the specification, the condition is a user ID and apassword for the simplification of description. However, the conditionis not limited thereto. For example, the condition may be otherinformation such as a date or a section to which a user belongs.Alternatively, the condition may be created by combining various piecesof information (for example, a date, a user ID, a password, and asection to which a user belongs may be combined). To handle anycomplicated condition (although the capacity is limited), in thespecification, the low-density region is larger than the high-densityregion.

FIG. 3 illustrates a part of the bar code plotted with a reference grid.FIG. 3 illustrates information dots 1401 and array dots 1402 whichdefine a bar code. The array dots 1402 are located on a reference grid1403 indicated by dotted lines, at a regular interval (in particular, onthe intersections of the reference grid 1403).

The information dots are located at positions shifted from theintersections of the reference grid 1403. The specific information isexpressed by shift directions of the information dots (directions inwhich the information dots are shifted from the intersections). Althoughthe reference grid is indicated by dotted lines in FIG. 3, the referencegrid is not actually printed.

Next, a process of extracting specific information from a document imagewill be described. As described above, the process of extracting thespecific information includes (1) finding bar codes from a documentimage, (2) acquiring information in the found bar codes to acquireembedded information, and (3) decoding the embedded information toacquire the specific information.

First, the method of (1) finding the bar codes from the document imagewill be described in detail with reference to FIG. 4.

The information acquisition unit 3 selects a desirable dot 1501 in adocument image. Then, the information acquisition unit 3 selects adesirable dot 1502 located near the selected dot. The informationacquisition unit 3 rotates the positions of the selected dots around acenter point between the dots by 90°. If other dots are present at theposition after the rotation, the information acquisition unit 3determines that the selected dots are the array dots which arevertically and horizontally arranged at a regular interval.

In contrast, if other dots are not present, the information acquisitionunit 3 determines that the selected dots are the information dots whichare arranged at random positions.

In this way, the information acquisition unit 3 finds the two arraydots, and then finds other array dots under the rule in which the arraydots are vertically and horizontally arranged at a regular interval. Theinformation acquisition unit 3 finds a plurality of array dots (forexample, 100 dots each in the horizontal and vertical directions), andthen virtually plots a reference grid on the reference dots. In thiscase, the reference grid has about 200 lines in the vertical direction,and about 200 lines in the horizontal direction. Thus, the referencegrid has about 400 lines in total. The number of lines is determinedwith reference to FIG. 3 (in FIG. 3, two array dots are arranged in thevertical direction and three array dots are arranged in the horizontaldirection, and hence three lines are arranged in the vertical directionand six lines are arranged in the horizontal direction).

In the first embodiment of the present invention, the above-describedprocesses (from the process of selecting a desirable dot to the processof virtually plotting the reference grid) are collectively calledfinding of bar codes. This is because a bar code must be present in aregion defined by this reference grid. In the following embodimentsincluding this embodiment, it is assumed that a bar code (including ahigh-density region and a low-density region) has a size equivalent to asize of a region defined by “vertically arranged 100lines”×“horizontally arranged 100 lines” (an interval between two linesis about 100 μm). The information acquisition unit 3 plots a referencegrid having a size that is at least twice the size of the aforementionedreference grid in the vertical and horizontal directions. Hence, atleast a single bar code is present in the reference grid.

The information acquisition unit 3 repeatedly performs theabove-described processes (from the process of selecting a desirable dotto the process of virtually plotting a reference grid) an N-number oftimes (for example, 20 times) while a subject region is changed. Forexample, the entire document image is divided into the N-number ofregions (e.g., vertically arranged 4 regions and horizontally arranged 5regions, that is, 20 regions in total), and the above-describedprocesses are repeated the N-number of times. By repeating theabove-described processes the N-number of times, even if a plurality ofbar code groups are present in a document image, at least a single barcode can be found from each of the bar code groups.

For example, there may be a case in which two documents are put on thedocument plate, copy inhibition information is added to the firstdocument, and conditional copy permission information is added to thesecond document. In this case, a plurality of bar code groups arepresent in document images. Even in this case, since the reference gridis plotted in the various regions, the information acquisition unit 3can find at least a single bar code included in each of the bar codegroups. That is, a bar code corresponding to the copy inhibitioninformation and a bar code corresponding to the conditional copypermission information can be found.

The given description is for the method of finding bar codes.

Next, the method of (2) acquiring the information in the found bar codesto acquire the embedded information will be described.

(2-1) The information acquisition unit 3 obtains the shift directions ofthe information dots from the intersections of the reference grid. Inthe aforementioned example, the vertically arranged 200 lines and thehorizontally arranged 200 lines are plotted. Thus, 40000 intersectionsin total are present. Among these 40000 intersections, array dots arepresent on 20000 intersections, and hence shift directions ofinformation dots are obtained from the residual 20000 intersections.Accordingly, 3-bit information is acquired for every information dot.

In particular, the information acquisition unit 3 acquires informationof 0 to 7 (3-bit information) such that 0 is acquired when aninformation dot is shifted to the upper side, 1 is acquired when aninformation dot is shifted to the upper right side, 2 is acquired whenan information dot is shifted to the right side, etc. (hereinafter, avalue of information is incremented by one as the direction is shiftedby 45°). As a result, information of 3 bits×20000=60000 bits can beacquired. The 60000-bit information includes embedded information.

(2-2) Next, a process of finding embedded information from the acquiredinformation (for example, 60000-bit information) will be described.

Though it is not described when the encoding process is described, theencoding unit 11 acquires embedded information such that a predeterminedbit string (for example, a bit string including 20 bits of01010101010101010101) is included at the start during encoding.

The information acquisition unit 3 finds the predetermined bit stringfrom the acquired information (for example, 60000-bit information).Then, the information acquisition unit 3 determines the information asthe embedded information until the next predetermined bit string isfound.

That is, the information acquisition unit 3 determines “thepredetermined bit string+the information string interposed between thepredetermined bit strings” as the embedded information. Thus, theinformation acquisition unit 3 acquires “the predetermined bitstring+the information string interposed between the predetermined bitstrings” as the embedded information.

The information acquisition unit 3 performs the aforementioned processes(processes of 2-1 and 2-2) for all the plural reference grids (i.e., 20reference grids).

The given description is for the method of (2) acquiring the informationin the bar codes to acquire the embedded information.

Finally, the process of (3) decoding the embedded information to acquirethe specific information will be described.

The control unit 1 that has found a single bar code decodes embeddedinformation included in a high-density region of the bar code. To bemore specific, an error correction code and a predetermined bit stringare removed (deleted) from the embedded information. Since the controlunit 1 performs decoding, the control unit 1 can acquire copy controlinformation and a document ID.

Also, when the control unit 1 acquires conditional copy permissioninformation as the copy control information, the control unit 1 decodesembedded information included in a low-density region to acquire acondition. The low-density region is not always decoded, but is decodedonly when the conditional copy permission information is acquiredbecause the data size of the embedded information in the low-densityregion is larger than the data size of the high-density region and hencedecoding for the embedded information in the low-density region may takea time.

The given description is for the process of (3) decoding the embeddedinformation to acquire the specific information.

The above-described process series is called “extraction.” By performingthe extraction process, the specific information can be acquired fromthe document image.

Next, control for copying executed by the MFP that has a function ofinhibiting unauthorized copying will be described in detail withreference to FIGS. 1 and 7. FIG. 7 is a flowchart showing a flow ofcontrol for copying executed by the MFP according to this embodiment. Itis to be noted that the MFP is a copier that can add and extractspecific information.

A user who wants to make a copy of a document with bar codes mergedinputs a user ID and a password through the operation unit 5 whilewatching the setting screen 3002 displayed on the display unit 9. Theinformation input through the operation unit 5 is sent from theoperation unit 5 to the user authentication unit 6. The userauthentication unit 6 determines whether the input password is correctwith reference to the managed information (S2301).

In step S2301, if the user authentication unit 6 determines that thepassword is not correct, the MFP waits for the input of the correctpassword.

In step S2301, if the user authentication unit 6 determines that thepassword is correct, the user authentication unit 6 sends thedetermination of the correct password and the user ID to the controlunit 1. The control unit 1 that has received the determination of thecorrect password and the user ID causes the display unit 9 to display anotification that allows a user to give a copy start instruction.

Then, the user inputs the copy start instruction through the operationunit 5. Then, the operation unit 5 notifies the start of copying to thecontrol unit 1. The control unit 1 controls the reading unit 2 to readthe document. The document image generated in this way is sent to thememory 7 and the information acquisition unit 3 (S2302). If a pluralityof documents to be read by the reading unit 2 are present, documentimages for the plural documents are generated. When the memory 7receives the document image, the control unit 1 starts to execute imageprocessing for the document image. The image processing is required forthe document image to allow the output unit 8 to print the documentimage (for example, half toning).

Next, the information acquisition unit 3 finds a bar code from thedocument image, and acquires information in the found bar code toacquire embedded information (S2303). As described above, the process inS2303 is performed the N-number of times (for example, 20 times), andhence 20 pieces of the embedded information are possibly acquired atmaximum.

Next, the control unit 1 asks the information acquisition unit 3 whetherthe bar-code information acquiring process executed in step S2302 hasbeen completed (S2304). If the bar-code information acquiring processhas not been completed, the flow returns to the process in step S2303.

If the information acquisition unit 3 has completed the bar-codeinformation acquiring process in step S2304, the control unit 1determines whether the information acquisition unit 3 has acquired atleast a piece of embedded information from the document image in thebar-code information acquiring process (S2305).

If the information acquisition unit 3 has acquired at least a singlepiece of embedded information from the document image in step S2305, thecontrol unit 1 decodes information in a high-density region of theacquired embedded information (S2306).

Then, the control unit 1 acquires copy control information and adocument ID in specific information. The copy control information mayinclude either or both copy inhibition information and conditional copypermission information.

Next, the control unit 1 determines whether the information in thehigh-density region of the embedded information has been decodedsuccessfully (S2307).

If the control unit 1 determines that the information in thehigh-density region of the embedded information has been decodedsuccessfully in step S2307, the control unit 1 determines whetherdecoding of all information in the high-density region of the embeddedinformation has been completed (S2308).

If the control unit 1 determines that decoding of all information in thehigh-density region of the embedded information has not been completedin step S2308, the control unit 1 stops the copy operation of the MFP.That is, the document image generated by the reading unit 2 is notoutput.

If the control unit 1 determines that all information of the embeddedinformation has been completed in step S2308, the control unit 1determines whether the copy control information includes copy inhibitioninformation (S2309).

If the control unit 1 determines that the copy control informationincludes the copy inhibition information in S2309, the control unit 1stops the copy operation of the MFP. That is, the document imagegenerated by the reading unit 2 is not output.

If the MFP has extracted the copy inhibition information and theconditional copy permission information in the process in step S2309(that is, if the copy control information acquired in S2306 includesboth), no document is copied. In other words, the document, to which theconditional copy permission information is added and which should becopied, and the document, to which the copy inhibition information isadded, are not copied. That is, if both information is extracted, theMFP (the control unit 1 included therein) gives preference to the copyinhibition information and inhibits the document from being copied. As aresult, the behavior of the malicious user can be prevented from makingan unauthorized copy of the document to which the copy inhibitioninformation is added by using the document to which the conditional copypermission information is added.

In this case, the control unit 1 performs control not to request theuser to input the condition associated with the conditional copypermission information. That is, the display unit 9 does not display thescreen to allow the user to input information corresponding to thecondition. The condition associated with the conditional copy permissioninformation is a condition included in a bar code that is equivalent tothe bar code from which the conditional copy permission information isacquired.

If the control unit 1 determines that the copy control information doesnot include the copy inhibition information in S2309, the control unit 1determines whether a predetermined (for example, two) or larger numberof pieces of copy permission information associated with differentdocument IDs have been extracted (S2310). The conditional copypermission information associated with the document ID is conditionalcopy permission information included in a bar code that is equivalent tothe bar code from which the document ID is acquired.

If the control unit 1 determines that the predetermined or larger number(for example, two) of pieces of the conditional copy permissioninformation associated with the different document IDs have beenextracted in S2310, the control unit 1 stops the copy operation of theMFP. That is, the document image generated by the reading unit 2 is notoutput.

The document image is not output in such a case (i.e., in the case inwhich the predetermined or larger number of pieces of the conditionalcopy permission information have been extracted), in order to inhibitthe malicious user from making a copy of the document. Making anunauthorized copy by the malicious user may be the behavior as follows.

The behavior is such that a user puts a document, to which conditionalcopy permission information including a condition that the user knows isadded, on a document plate simultaneously with a document, to whichconditional copy permission information including a condition that theuser does not know is added, so as to make a copy of the document towhich the conditional copy permission information including thecondition that the user does not know is added.

In this case (i.e., in the case in which the predetermined or largernumber of pieces of the conditional copy permission information havebeen extracted), according to the first embodiment of the presentinvention, conditions associated with the conditional copy permissioninformation which have been extracted by the predetermined or largernumber of pieces are not extracted. That is, decoding is not performedfor a low-density region of embedded information. Decoding is notperformed because the execution speed of other jobs (for example,copying of another document, printing of another document image,transmission of another document image) may be delayed while the MFPextracts the conditions. If the execution speed of other jobs do nothave to be considered, of course, the conditions associated with theconditional copy permission information which have been extracted by thepredetermined or larger number of pieces can be acquired.

In contrast, if a smaller number than the predetermined number of piecesof the conditional copy permission information associated with differentdocument IDs have been extracted, as long as all conditions for thesmaller number of pieces of the information extracted are satisfied,copies of document images are made (S2311, S2312, S2313). Occasionally,the number of conditions for the smaller number of pieces of theinformation may be only one. In this case, satisfying only a singlecondition is satisfying all conditions for the smaller number of piecesof the information.

Now, it is assumed that a plurality of (for example, a predeterminednumber or larger number of) documents to which conditional copypermission information is added are put on the document plate. In such asituation, it is also assumed that different document IDs are added tothe documents. Then, the number of the document IDs is a predeterminednumber or larger, and the pieces of the conditional copy permissioninformation associated with the different document IDs are extracted.Hence, no document is copied. In contrast, it is assumed that therespective documents have the same document ID. Then, the number ofpieces of the conditional copy permission information becomes one, andthe number of the document IDs becomes smaller than the predeterminednumber. Hence, (if the condition is satisfied) the document images canbe copied. The copies of the respective documents are made when the samedocument ID is added to the respective documents because the documentsare created by a single copy operation and making copies of suchdocuments is hardly unauthorized copying.

If the control unit 1 determines that the predetermined or larger numberof pieces of the conditional copy permission information associated withthe different document IDs have not been extracted (for example, if onlya piece of the conditional copy permission information has beenextracted) in S2310, the MFP acquires all conditions associated with thesmaller number than the predetermined number of pieces of theconditional copy permission information (S2311). That is, the controlunit 1 decodes the embedded information in the low-density region.

If the extracted condition includes a password, the control unit 1causes the display unit 9 to display the screen to request the user toinput information corresponding to the condition (i.e., password). Incontrast, if the extracted condition does not include a password (forexample, all conditions are user IDs), the display unit 9 does not haveto display any particular screen. This is because the informationcorresponding to the condition (i.e., user ID) has been already inputfor user authentication.

Then, the control unit 1 determines whether the information input by theuser satisfies all conditions extracted in S2311 (S2312).

If the control unit 1 determines that the input information satisfiesall conditions in S2312, the MFP starts to output the document images(S2313). For example, when the user ID sent in S2301 matches with thesolely extracted condition (in this case, the user ID in the extractedcondition), the copy operation is started accordingly.

If the user has the other document to be scanned, the user removes thedocument from the document plate and puts the other document on thedocument plate. Then, when the user inputs a copy start instructionthrough the operation unit 5, the MFP executes the process from S2302.

In contrast, if the control unit 1 determines that the condition is notsatisfied in S2312, the control unit 1 stops the copy operation of theMFP. That is, a copy of the document image generated by the reading unit2 is not made.

The given description is for the control for copying executed by the MFPthat has a function of inhibiting unauthorized copying.

Second Embodiment

In a second embodiment of the present invention, control for copyingexecuted by a MFP different from the control according to the firstembodiment of the present invention will be described. First, part thatis different from the first embodiment of the present invention will bedescribed.

Copy control information in the second embodiment of the presentinvention includes copy permission information in addition toconditional copy permission information and copy inhibition information.If the MFP reads a document to which the copy permission information isadded, the MFP makes a copy of the document without requesting a user toinput a condition, unlike the conditional copy permission information.That is, if a copy of the document, to which the copy permissioninformation is added, is made, the user can make a copy of the documentwithout condition.

Since the copy permission information is additionally included in thecopy control information, the specific information includes two piecesof information of copy permission information and a document ID.

Next, an operation performed by a user and a process performed by theMFP in accordance with the operation by the user to add specificinformation will be described in detail with reference to FIG. 6( b). Inthe second embodiment of the present invention, an option to “permitcopy” is added in a print security setting dialogue box 31. If the userselects this option, the copy permission information and the document IDare added as the specific information to a document to be printed. Thebehavior when that option is selected is similar to that in the firstembodiment of the present invention.

Other part not described herein is similar to that in the firstembodiment of the present invention. More specifically, theconfiguration of the MFP, the process of creating the document to whichthe specific information is added, and the process of extracting thespecific information from a document to which the specific informationis added in the form of bar codes, are similar to those in the firstembodiment. That is, the MFP can extract the specific information.

Next, control for copying executed by the MFP that has a function ofinhibiting unauthorized copying will be described in detail according tothe second embodiment of the present invention. The control additionallyincludes a step (S2308.5) between S2308 and S2309 in the flowchart shownin FIG. 7. S2308.5 is a step of determining whether a predetermined orlarger number of pieces of copy permission information associated withdifferent document IDs have been extracted. Hereinafter, part that ischanged because this step is added will be described.

If the control unit 1 determines that decoding of all embeddedinformation has been completed in step S2308, the control unit 1determines whether a predetermined or larger number of pieces of thecopy permission information associated with the different document IDshave been extracted. The predetermined number is desirably larger thanthe aforementioned predetermined number. This is because the behavior ofsimultaneously making copies of documents to which copy permissioninformation is added may have less intension of making unauthorizedcopies than the behavior of simultaneously making copies of documents towhich conditional copy permission information is added.

If the control unit 1 determines that the predetermined or lager numberof pieces of the copy permission information have been extracted, thecontrol unit 1 stops the copy operation of the MFP. That is, thedocument image generated by the reading unit 2 is not output. Then, thecontrol unit 1 progresses the process to the “end” of the flowchart inFIG. 7.

The document image is not output in such a case (i.e., in the case inwhich the predetermined or larger number of pieces of the copypermission information have been extracted), in order to inhibit themalicious user from making a copy of the document. Making anunauthorized copy by the malicious user may be such that a user puts aplurality of documents, to which copy permission information is added,on a document plate, and then the user puts a document, to which copyinhibition information is added, to make a copy of the document.

In this case, major part of a generated document image includes barcodes of copy permission information, and residual part includes copyinhibition information. Thus, the information acquisition unit 3 lesslikely finds a bar code including the copy inhibition information. Ofcourse, the information acquisition unit 3 can theoretically find thebar code including the copy inhibition information. However, if the barcode is contaminated, such a bar code is less likely found. In light ofthis, the new step (S2308.5) is added to inhibit the malicious user frommaking an unauthorized copy.

The control for copying is described. If the control unit 1 determinesthat the predetermined (for example, five) or larger number of pieces ofthe copy permission information have not been extracted, the controlunit 1 progresses the process to S2309, and determines whether the copyinhibition information has been extracted (S2309).

If the control unit 1 determines that the copy inhibition informationhas been extracted (if YES in S2309), the control unit 1 stops the copyoperation of the MFP. That is, the document image generated by thereading unit 2 is not output.

If the MFP has extracted the copy inhibition information and the copypermission information in this process (that is, if the copy controlinformation acquired in S2306 includes both), no document is copied. Inother words, the document, to which the copy permission information isadded and which should be copied, and the document, to which the copyinhibition information is added, are not copied. As a result, thebehavior of the malicious user can be prevented from making anunauthorized copy of the document to which the copy inhibitioninformation is added by using the document to which the copy permissioninformation is added.

In contrast, if the control unit 1 determines that the copy inhibitioninformation has not been extracted (if NO in S2309), the control unit 1determines whether a predetermined (for example, two) or larger numberof pieces of the conditional copy permission information associated withdifferent document IDs have been extracted (S2310).

If the control unit 1 determines that the predetermined or larger numberof the copy permission information associated with the differentdocument IDs have been extracted (if YES in S2310), the control unit 1stops the copy operation of the MFP. That is, the document imagegenerated by the reading unit 2 is not copied.

In contrast, if the control unit 1 determines that the predetermined orlarger number of pieces of the conditional copy permission informationassociated with the different document IDs have not been extracted (ifNO in S2310), the control unit 1 determines whether the copy permissioninformation and the conditional copy permission information have beenextracted (S2310.3). This step (S2310.3) is also additionally includedin the flowchart in FIG. 7.

If the control unit 1 determines that the copy permission informationand the conditional copy permission information have been extracted (ifYES in S2310.3), the control unit 1 stops the copy operation of the MFP.That is, the document image generated by the reading unit 2 is notoutput.

In contrast, if the control unit 1 determines that the copy permissioninformation and the conditional copy permission information have notbeen extracted (if NO in S2310.3), the control unit 1 determines whetheronly the copy permission information has been extracted (S2310.6). Thatis, it is determined whether only the copy permission information hasbeen extracted while the copy inhibition information or the conditionalcopy permission information is not extracted. If the control unit 1determines that only the copy permission information has been extracted,the document image is output. In contrast, if the control unit 1determines that the extracted information is not only the copypermission information, the process is executed from S2311 in theflowchart shown in FIG. 7. Other part not described herein is subjectedto the operation control similar to that in the first embodiment of thepresent invention.

As it is found through the processes, the second embodiment of thepresent invention aims at such a user who uses a document, to which copypermission information is added, that is, which is copied withoutcondition to make a copy of another document, to which conditional copypermission information including a condition that the user does not knowis added. In particular, in this embodiment, the user is not onlyinhibited from making a copy of another document, but also from making acopy of the document (the document to which the copy permissioninformation is added) as a penalty.

Other Embodiments

Described above is inhibition of making a copy of a document undervarious circumstances. However, a subject for inhibition is not limitedto a copy operation. For example, outputting, for example, transmittinga document image to an external device may be inhibited. Regarding this,the copy inhibition information is called output inhibition information,the conditional copy permission information is called conditional outputpermission information, and the copy permission information is calledoutput permission information.

In this specification, a bar code is an image that representsinformation in accordance with the thickness of a line and the positionof a dot. The processes performed by the MFP have been described aboveon the basis of an exemplary form of a bar code. However, personsskilled in the art can replace the bar code in the above-described formwith a bar code in a different form (for example, a two-dimensional barcode, such as a QR code or a griff code, or a bar code of a typicallyused type including a plurality of bars). Alternatively, the bar code inthe above-described form may be replaced with a watermark or a mark.However, if a mark is used, different shapes of marks have to be definedfor different pieces of information. Also, in this case, the MFPdetermines information indicated by a predetermined mark by using anexisting pattern matching technique. The process of determining theinformation indicated by the predetermined mark by the pattern matchingtechnique is also called extraction of information in thisspecification. Also, the watermark, the predetermined mark, and otherbar codes in various forms are collectively called embedded images.

The determination has been made for the information indicated by thepredetermined mark by using the pattern matching technique.Alternatively, the MFP does not have to determine the informationindicated by the predetermined mark, and may control outputting (forexample, copying) in accordance with the predetermined mark when thepredetermined mark is found. For example, the MFP may inhibit a copyoperation when the MFP detects a mark of “∘ (white circle).” Thus, whenthe MFP finds the “∘,” the copy operation is stopped in accordance withthe mark of the “∘.” The same can be said to the conditional copypermission information. When the MFP finds a predetermined mark, the MFPcontrols outputting in accordance with the predetermined mark. In thiscase, a bar code or a watermark is not decoded. Outputting is controlledmerely with reference to the shape of the image. In this specification,finding a predetermined mark is called “detection” of a predeterminedmark.

In the above-described embodiments, the high-density region and thelow-density region are provided, and important information is includedin the high-density region. Accordingly, an effect can be obtained suchthat important information can be more likely extracted correctly from adocument. However, persons skilled in the art may intentionally degradethe aforementioned effect. In this case, the densities in the regions donot have to be different from one another, and all regions in a bar codemay have the same density.

In the above-described embodiments, as a method of associating twopieces of information (for example, conditional copy permissioninformation and a document ID, or conditional copy permissioninformation and a condition) with one another, the method of allowingthe two pieces of information to be included in the same bar code hasbeen disclosed. However, the method of associating the two pieces ofinformation with one another may be another method. For example,predetermined information (for example, AAA) may be added to the startof the information, thereby associating the respective pieces ofinformation with one another.

In the above-described embodiments, the number of document IDs iscounted to identify the number of different bar codes. However, there isanother identification method. For example, if information relating to aversion of a bar code is added to a document, the MFP can identify thenumber of different bar codes with reference to a difference in versionsof the bar codes. The information for identifying the difference in barcodes (for example, a document ID or version information of a bar code)is collectively called document identification information.

In the above description, a single document ID is added to onlydocuments that are created by a single copy operation. However, a singledocument ID may be added to documents that are created by a single printoperation (for example, a print operation performed in response to aprint instruction from a personal computer).

In the above-described embodiments, a condition is expressed by a bitstring and then is bar-coded. However, the condition does not have to beexpressed in the direct form (in the form of a bit string directlycorresponding to the condition). That is, the condition does not have tobe bar-coded. Instead of the bar-coded condition, a hashed condition maybe bar-coded. In this case, the MFP has to hold a hash function used forhashing the condition. In the embodiments of the present invention, theMFP that adds specific information is the same as the MFP that extractsthe specific information. However, different MFPs may perform therespective processes. In this case, the MFP that adds a bar code and theMFP that extracts a bar code have to hold the same hash function. Thisis because, in a case in which the respective MFPs use different hashfunctions, even if a hashed condition is the same as a condition inputby a user, the values of the two hashed conditions do not correspond toone another.

When the hashed condition is bar-coded, the steps in the flowcharts inFIGS. 2 and 7 are modified as follows. In the flowchart in FIG. 2, astep of hashing a condition by using a hash function (S103.5) is addedbetween steps S103 and S104. In the process in step S103.5, thecondition is hashed and then bar-coded.

Also, in the flowchart in FIG. 7, a process of hashing an inputcondition by using a hash function is added to step S2312. In stepS2312, an extracted condition in a hashed state is compared with aninput condition in a hashed state.

Also, the present invention may be implemented by executing thefollowing processes. In particular, a software (program) that implementsthe function of any of the embodiments is supplied to a system or adevice through a network or through any of various recording media, anda computer (or CPU, MPU, etc.) in the system or the device reads andexecutes the program.

REFERENCE SIGNS LIST

-   -   1 control unit    -   2 reading unit    -   3 information acquisition unit    -   5 operation unit    -   6 user authentication unit    -   7 memory    -   8 output unit    -   9 display unit    -   10 data base    -   11 encoding unit

1. A device having a reading unit configured to read a document placedon a document plate for generating a document image in response to aninstruction from a user to start a copy, and a detection unit configuredto detect a bar code from the document image generated by the readingunit, the device comprising: a determination unit configured todetermine after the reading unit generates a document imagecorresponding to a plurality of sheets of a document in response to aninstruction from a user to start a copy with the plurality of sheets ofthe document being placed on the document plate, whether or not thenumber of bar codes detected by the detection unit from the documentimage is equal to or more than a predetermined number; and a controlunit configured to control not to print the generated document imagecorresponding to the plurality of sheets of the document in response tothe determination that the number of bar codes detected by the detectionunit is equal to or more than the predetermined number.
 2. The deviceaccording to claim 1, wherein the plurality of sheets of the documenthaving a bar code printed is a copy-permitted document with copypermission information being added which is permitted to be copiedwithout requesting a user to input condition information, and whereinthe control unit controls not to print the generated document imagecorresponding to the plurality of sheets of the document in response tothe determination that the number of detected bar codes corresponding tothe copy permission information is equal to or more than thepredetermined number, and controls to print the generated document imagecorresponding to the plurality of sheets of the document in response tothe determination that the number of detected bar codes corresponding tothe copy permission information is less than the predetermined number.3. The device according to claim 1, wherein the plurality of sheets ofthe document having a bar code printed is a conditional-copy-permitteddocument with conditional copy permission information being added whichis inhibited to be copied in a case where the conditional copypermission information added to the document does not match conditioninformation input by a user and permitted to be copied in a case wherethe conditional copy permission information added to the documentmatches condition information input by a user, and wherein the controlunit controls not to print the generated document image corresponding tothe plurality of sheets of the document in response to the determinationthat the number of detected bar codes corresponding to the conditionalcopy permission information is equal to or more than the predeterminednumber, and controls to print the generated document image correspondingto the plurality of sheets of the document in response to thedetermination that the number of detected bar codes corresponding to theconditional copy permission information is less than the predeterminednumber.
 4. The device according to claim 1, wherein the bar code is a QRcode.
 5. A method of controlling a device, the device having a readingunit configured to read a document placed on a document plate forgenerating a document image in response to an instruction from a user tostart a copy, and a detection unit configured to detect a bar code fromthe document image generated by the reading unit, the method comprising:determining after the reading unit generates a document imagecorresponding to a plurality of sheets of a document in response to aninstruction from a user to start a copy with the plurality of sheets ofthe document being placed on the document plate, whether or not thenumber of bar codes detected by the detection unit from the documentimage is equal to or more than a predetermined number; and controllingnot to print the generated document image corresponding to the pluralityof sheets of the document in response to the determination that thenumber of bar codes detected by the detection unit is equal to or morethan the predetermined number.
 6. The method according to claim 5,wherein the plurality of sheets of the document having a bar codeprinted is a copy-permitted document with copy permission informationbeing added which is permitted to be copied without requesting a user toinput condition information, and wherein the controlling step furthercomprises controlling not to print the generated document imagecorresponding to the plurality of sheets of the document in response todetermining that the number of detected bar codes corresponding to thecopy permission information is equal to or more than the predeterminednumber, and controlling to print the generated document imagecorresponding to the plurality of sheets of the document in response todetermining that the number of detected bar codes corresponding to thecopy permission information is less than the predetermined number. 7.The method according to claim 5, wherein the plurality of sheets of thedocument having a bar code printed is a conditional-copy-permitteddocument with conditional copy permission information being added whichis inhibited to be copied in a case where the conditional copypermission information added to the document does not match conditioninformation input by a user and permitted to be copied in a case wherethe conditional copy permission information added to the documentmatches condition information input by a user, and wherein thecontrolling step further comprises controlling not to print thegenerated document image corresponding to the plurality of sheets of thedocument in response to determining that the number of detected barcodes corresponding to the conditional copy permission information isequal to or more than the predetermined number, and controlling to printthe generated document image corresponding to the plurality of sheets ofthe document in response to determining that the number of detected barcodes corresponding to the conditional copy permission information isless than the predetermined number.
 8. The method according to claim 5,wherein the bar code is a QR code.
 9. A non-transitory computer-readablemedium having instructions recorded thereon, which, when executed by acomputer, cause the computer to perform a method of controlling adevice, the device having a reading unit configured to read a documentplaced on a document plate for generating a document image in responseto an instruction from a user to start a copy, and a detection unitconfigured to detect a bar code from the document image generated by thereading unit, the method comprising: determining after the reading unitgenerates a document image corresponding to a plurality of sheets of adocument in response to an instruction from a user to start a copy withthe plurality of sheets of the document being placed on the documentplate, whether or not the number of bar codes detected by the detectionunit from the document image is equal to or more than a predeterminednumber; and controlling not to print the generated document imagecorresponding to the plurality of sheets of the document in response tothe determination that the number of bar codes detected by the detectionunit is equal to or more than the predetermined number.
 10. Thenon-transitory computer-readable medium according to claim 9, whereinthe plurality of sheets of the document having a bar code printed is acopy-permitted document with copy permission information being addedwhich is permitted to be copied without requesting a user to inputcondition information, and wherein the controlling step furthercomprises controlling not to print the generated document imagecorresponding to the plurality of sheets of the document in response todetermining that the number of detected bar codes corresponding to thecopy permission information is equal to or more than the predeterminednumber, and controlling to print the generated document imagecorresponding to the plurality of sheets of the document in response todetermining that the number of detected bar codes corresponding to thecopy permission information is less than the predetermined number. 11.The non-transitory computer-readable medium according to claim 9,wherein the plurality of sheets of the document having a bar codeprinted is a conditional-copy-permitted document with conditional copypermission information being added which is inhibited to be copied in acase where the conditional copy permission information added to thedocument does not match condition information input by a user andpermitted to be copied in a case where the conditional copy permissioninformation added to the document matches condition information input bya user, and wherein the controlling step further comprises controllingnot to print the generated document image corresponding to the pluralityof sheets of the document in response to determining that the number ofdetected bar codes corresponding to the conditional copy permissioninformation is equal to or more than the predetermined number, andcontrolling to print the generated document image corresponding to theplurality of sheets of the document in response to determining that thenumber of detected bar codes corresponding to the conditional copypermission information is less than the predetermined number.
 12. Thenon-transitory computer-readable medium according to claim 9, whereinthe bar code is a QR code.